dijit/Tree examples

Detect when tree has finished loading

Use the onLoadDeferred to detect when the Tree has finished loading

var tree = registry.byId('myTree');

// Connect to tree onLoad to do work once it has initialized
tree.onLoadDeferred.then(function(){
    console.debug("tree onLoad here!");
    dojo.disconnect(tmph);

    // do work here
});

Expanding and selecting tree nodes programmatically

There are a number of flags and methods for expanding/collapsing the tree and for selecting certain nodes.

If the autoExpand flag is passed to the constructor, the Tree is initially shown with all nodes expanded.

You can then call collapseAll() and expandAll() to collapse and expand the Tree, respectively.

Also, dijit.Tree has a paths attribute, which can be set with the usual tree.set('paths', [path1, path2]) syntax, where each path is an array of item id’s, starting with the root node and going down to the leaf. It serves two purposes: to expand the Tree to the specified nodes, and to select those nodes.

Combining those all together into an example:

require(["dojo/parser", "dojo/store/Memory", "dijit/tree/ObjectStoreModel", "dijit/Tree"]);
<div data-dojo-type="dojo/store/Memory" data-dojo-id="myStore">
    <!-- Create store with inlined data.
        For larger data sets should use dojo.store.JsonRest etc. instead of dojo.store.Memory. -->
    <script type="dojo/method">
         this.setData([
            { id: 'world', name:'The earth', type:'planet', population: '6 billion'},
            { id: 'AF', name:'Africa', type:'continent', population:'900 million', area: '30,221,532 sq km',
                    timezone: '-1 UTC to +4 UTC', parent: 'world'},
                { id: 'EG', name:'Egypt', type:'country', parent: 'AF' },
                { id: 'KE', name:'Kenya', type:'country', parent: 'AF' },
                    { id: 'Nairobi', name:'Nairobi', type:'city', parent: 'KE' },
                    { id: 'Mombasa', name:'Mombasa', type:'city', parent: 'KE' },
                { id: 'SD', name:'Sudan', type:'country', parent: 'AF' },
                    { id: 'Khartoum', name:'Khartoum', type:'city', parent: 'SD' },
            { id: 'AS', name:'Asia', type:'continent', parent: 'world' },
                { id: 'CN', name:'China', type:'country', parent: 'AS' },
                { id: 'IN', name:'India', type:'country', parent: 'AS' },
                { id: 'RU', name:'Russia', type:'country', parent: 'AS' },
                { id: 'MN', name:'Mongolia', type:'country', parent: 'AS' },
            { id: 'OC', name:'Oceania', type:'continent', population:'21 million', parent: 'world'},
            { id: 'EU', name:'Europe', type:'continent', parent: 'world' },
                { id: 'DE', name:'Germany', type:'country', parent: 'EU' },
                { id: 'FR', name:'France', type:'country', parent: 'EU' },
                { id: 'ES', name:'Spain', type:'country', parent: 'EU' },
                { id: 'IT', name:'Italy', type:'country', parent: 'EU' },
            { id: 'NA', name:'North America', type:'continent', parent: 'world' },
            { id: 'SA', name:'South America', type:'continent', parent: 'world' }
        ]);
    </script>
    <script type="dojo/method" data-dojo-event="getChildren" data-dojo-args="object">
         // Supply a getChildren() method to store for the data model where
         // children objects point to their parent (aka relational model)
         return this.query({parent: this.getIdentity(object)});
    </script>
</div>

<!-- Create the model bridging the store and the Tree -->
<div data-dojo-type="dijit/tree/ObjectStoreModel" data-dojo-id="myModel"
  data-dojo-props="store: myStore, query: {id: 'world'}"></div>

<!-- buttons to test Tree features -->
<button onclick="mytree.collapseAll();">
    Collapse all
</button>
<button onclick="mytree.expandAll();">
    Expand all
</button>
<button onclick="mytree.set('paths', [ ['world', 'AF', 'KE', 'Nairobi'], ['world', 'SA'] ] );">
    Select Nairobi, South America
</button>

<!-- Create the tree -->
<div data-dojo-type="dijit/Tree" data-dojo-id="mytree"
        data-dojo-props="model: myModel, autoExpand: true"></div>

One complication with using ‘paths’ is that you must know the full path to the node in your data you are trying to select. (And by the way, there may be more than one path to a node, if your Tree has nodes with multiple parents.)

The solution to that problem will depend greatly on your data layout, and the query capabilities of your store.

Making nodes expand by clicking on the label

Nodes always expand/collapse by clicking on the [+] icon, but to make a node expand when clicking on the label, simply set the openOnClick attribute to true

require(["dojo/parser", "dojo/store/Memory", "dijit/tree/ObjectStoreModel", "dijit/Tree"]);
<div data-dojo-type="dojo/store/Memory" data-dojo-id="memoryStore">
    <!-- Create store with inlined data.
        For larger data sets should use dojo.store.JsonRest etc. instead of dojo.store.Memory. -->
    <script type="dojo/method">
         this.setData([
            { id: 'world', name:'The earth', type:'planet', population: '6 billion'},
            { id: 'AF', name:'Africa', type:'continent', population:'900 million', area: '30,221,532 sq km',
                    timezone: '-1 UTC to +4 UTC', parent: 'world'},
                { id: 'EG', name:'Egypt', type:'country', parent: 'AF' },
                { id: 'KE', name:'Kenya', type:'country', parent: 'AF' },
                    { id: 'Nairobi', name:'Nairobi', type:'city', parent: 'KE' },
                    { id: 'Mombasa', name:'Mombasa', type:'city', parent: 'KE' },
                { id: 'SD', name:'Sudan', type:'country', parent: 'AF' },
                    { id: 'Khartoum', name:'Khartoum', type:'city', parent: 'SD' },
            { id: 'AS', name:'Asia', type:'continent', parent: 'world' },
                { id: 'CN', name:'China', type:'country', parent: 'AS' },
                { id: 'IN', name:'India', type:'country', parent: 'AS' },
                { id: 'RU', name:'Russia', type:'country', parent: 'AS' },
                { id: 'MN', name:'Mongolia', type:'country', parent: 'AS' },
            { id: 'OC', name:'Oceania', type:'continent', population:'21 million', parent: 'world'},
            { id: 'EU', name:'Europe', type:'continent', parent: 'world' },
                { id: 'DE', name:'Germany', type:'country', parent: 'EU' },
                { id: 'FR', name:'France', type:'country', parent: 'EU' },
                { id: 'ES', name:'Spain', type:'country', parent: 'EU' },
                { id: 'IT', name:'Italy', type:'country', parent: 'EU' },
            { id: 'NA', name:'North America', type:'continent', parent: 'world' },
            { id: 'SA', name:'South America', type:'continent', parent: 'world' }
        ]);
    </script>
    <script type="dojo/method" data-dojo-event="getChildren" data-dojo-args="object">
         // Supply a getChildren() method to store for the data model where
         // children objects point to their parent (aka relational model)
         return this.query({parent: object.id});
    </script>
</div>

<!-- Create the model bridging the store and the Tree -->
<div data-dojo-type="dijit/tree/ObjectStoreModel" data-dojo-id="myModel"
  data-dojo-props="store: memoryStore, query: {id: 'world'}"></div>

<!-- Create the tree -->
<div data-dojo-type="dijit/Tree" id="mytree"
    data-dojo-props="model: myModel, openOnClick: true"></div>

Rich Text Labels

In this example, _createTreeNode() is overridden to allow HTML markup in the tree. This is a hack, in the sense that the formatting may not be perfect for large (in pixels) elements. But the tree will display and work properly regardless, and for simple markup, ex: bold, it works great.

require([
    "dojo/_base/declare", "dojo/_base/window", "dojo/store/Memory",
    "dijit/tree/ObjectStoreModel", "dijit/Tree",
    "dojo/domReady!"
], function(declare, win, Memory, ObjectStoreModel, Tree){

    // Create test store, adding getChildren() method needed by ObjectStoreModel
    var store = new Memory({
        data: [
            { id: 0, label: "root"},
               {id: 1, label: "<i>hello</i>", parent: 0},
               {id: 2, label: "<b>world</b>", parent: 0},
        ],
        getChildren: function(object){
            return this.query({parent: object.id});
        }
    });

    // Create the model
    var model = new ObjectStoreModel({
        store: store,
        query: {id: 0},
        labelAttr: "label"
    });

    // Custom TreeNode class (based on dijit.TreeNode) that allows rich text labels
    var MyTreeNode = declare(Tree._TreeNode, {
        _setLabelAttr: {node: "labelNode", type: "innerHTML"}
    });

    // Create the Tree.
    var tree = new Tree({
        model: model,
        _createTreeNode: function(args){
           return new MyTreeNode(args);
        }
    });
    tree.placeAt(win.body());
    tree.startup();
});
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